A 26-year-old lady was referred for evaluation of dysphagia. The patient had consumed 50 ml of organophosphorus (OP) components of liquid pesticide 4 months ago and was on ventilatory support with a tracheostomy tube because of OP-poisoning-induced respiratory failure. Treatment included injection of atropine, pralidoxime and other supportive care, and the patient recovered. The patient developed dysphagia after extubation of the tracheostomy tube, and a percutaneous endoscopic gastrostomy (PEG) feeding tube was placed to support her nutritional status. Clinically, there was no neurological deficit. Figure 1 shows the esophagogastroduodenoscopy (OGD). What is the diagnosis?